/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.animation;

// Need the following import to get access to the app resources, since this
// class is in a sub-package.
import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import com.example.android.apis.R;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RadialGradient;
import android.graphics.Shader;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.OvalShape;
import android.os.Bundle;
import android.view.View;
import android.view.animation.AccelerateInterpolator;
import android.widget.Button;
import android.widget.LinearLayout;

public class ReversingAnimation extends Activity {

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.animation_reversing);
		LinearLayout container = (LinearLayout) findViewById(R.id.container);
		final MyAnimationView animView = new MyAnimationView(this);
		container.addView(animView);

		Button starter = (Button) findViewById(R.id.startButton);
		starter.setOnClickListener(new View.OnClickListener() {
			public void onClick(View v) {
				animView.startAnimation();
			}
		});

		Button reverser = (Button) findViewById(R.id.reverseButton);
		reverser.setOnClickListener(new View.OnClickListener() {
			public void onClick(View v) {
				animView.reverseAnimation();
			}
		});

	}

	public class MyAnimationView extends View implements
			ValueAnimator.AnimatorUpdateListener {

		public final ArrayList<ShapeHolder> balls = new ArrayList<ShapeHolder>();
		ValueAnimator bounceAnim = null;
		ShapeHolder ball = null;

		public MyAnimationView(Context context) {
			super(context);
			ball = createBall(25, 25);
		}

		private void createAnimation() {
			if (bounceAnim == null) {
				bounceAnim = ObjectAnimator.ofFloat(ball, "y", ball.getY(),
						getHeight() - 50f).setDuration(1500);
				bounceAnim.setInterpolator(new AccelerateInterpolator(2f));
				bounceAnim.addUpdateListener(this);
			}
		}

		public void startAnimation() {
			createAnimation();
			bounceAnim.start();
		}

		public void reverseAnimation() {
			createAnimation();
			bounceAnim.reverse();
		}

		public void seek(long seekTime) {
			createAnimation();
			bounceAnim.setCurrentPlayTime(seekTime);
		}

		private ShapeHolder createBall(float x, float y) {
			OvalShape circle = new OvalShape();
			circle.resize(50f, 50f);
			ShapeDrawable drawable = new ShapeDrawable(circle);
			ShapeHolder shapeHolder = new ShapeHolder(drawable);
			shapeHolder.setX(x - 25f);
			shapeHolder.setY(y - 25f);
			int red = (int) (Math.random() * 255);
			int green = (int) (Math.random() * 255);
			int blue = (int) (Math.random() * 255);
			int color = 0xff000000 | red << 16 | green << 8 | blue;
			Paint paint = drawable.getPaint(); // new
												// Paint(Paint.ANTI_ALIAS_FLAG);
			int darkColor = 0xff000000 | red / 4 << 16 | green / 4 << 8 | blue
					/ 4;
			RadialGradient gradient = new RadialGradient(37.5f, 12.5f, 50f,
					color, darkColor, Shader.TileMode.CLAMP);
			paint.setShader(gradient);
			shapeHolder.setPaint(paint);
			return shapeHolder;
		}

		@Override
		protected void onDraw(Canvas canvas) {
			canvas.save();
			canvas.translate(ball.getX(), ball.getY());
			ball.getShape().draw(canvas);
			canvas.restore();
		}

		public void onAnimationUpdate(ValueAnimator animation) {
			invalidate();
		}

	}
}